Control mechanism



April 28, 1925.

J. R. BUCHANAN CONTROL MECHANISM Filed Aug. '7, 1922 2 Sheets-Sheet l A ril zs, 1925. I 1,535,569 J. R. BUCHANAN V CONTROL MECHANISM Filed 1922 2 Sheets-Sheen" 2 k 0 S (3 F 1% Q Patented Apr. 28, 1925.

UNITED STATES JAMES RAMSEY BUCHANAN, OF SYLVA, NORTH CAROLINA.

CONTROL. MECHANISM.

Application filed August '7, 1922. Serial No. 580,338.

'1'0 all whom it may concern: 1

Be it known that I, Jaerns 1i. BUCHANAN, a citizen of the United States, residing at Sylva, in the county of Jackson and State of Yorth Carolina, have invented certain new and useful Improvements in Control Mechanism, of which the following is a specification.

This invention relates to control mechanism, and more particularly to an automatic cut off for conveyors.

An object of the invention is the provision of means for stopping a conveyor when the conveyor breaks or any part of the conveyor gets out of order.

A further object is the provision of an electrical control consisting of a pair of spaced contacts, and means for bridging said contacts when the conveyor breaks.

In the present invention, I provide a pair of spaced contacts, and a rocking beam con trolled by the conveyor. The beam is adapt ed to maintain a movable contact nen'iber in raised position and when said beam comes to a state of rest, due to a break in the conveyor, the movable contact member is permitted to bridge said spaced contact members to complete an electric circuit and cut oil the power operating the conveyor.

In the accompanying drawings, I have shown one embodiment of the invention. vIn this showing: 1

Figure 1 is a front elevation of the con trol device,

Figure 2is an end elevation, V

Figure 3 is a diagrammatic view of the device applied to a conveyor,

Figure 4 is a vertical sectional view on line 4-4 of Figure 1, and,

Figure 5 is a diagrammatic view showing the electrical circuits. 5

Referring to the drawings, the reference numeral 1 designates a panel or supporting board adapted to be arranged beside a conveyor. "A box or cover 2 is arranged on this board and is adapted to house the mechanism forming a part of the invention. A pair of cylinders 3 are arranged on the board, the cylinders being closed at their lower ends, and provided wsth openings 4 in their upper ends (see Figure 4). The cylinders are supported on the panel board in any suitable manner, as by clips 5. Pistons 6 are mounted in the cylinders and these pistons are provided with valves '7 which permit free flow of air or liquid from the top of the cylinder to the bottom and retard flow in the opposite direction. The pistons are provided with piston rods 8 extending through the top of the cylinder and provided with threaded upper ends 9. Nuts 10 are mounted on the threaded ends of the piston rods. A rocking beam 11 is pivoted at 12 on the board, and this beam is provided with a crank arm 13 connected thereto, as at 14. The other end of the crank arm is connected to a disk or wheel 15, mounted on a shaft 16. The beam 11 is provided with clips or brackets 17, having openings for the reception of the piston rods through which the piston rods freely pass. A contact member 18 is mounted on each of the piston rods.

In applying the device to a conveyor, the conveyor consists of anendless belt or chain 19, passing over sprockets 20 and 21 respectively. As shown, the sprocket 20 is the drive sprocket and is mounted on a shaft 22, having a pulley A belt 24 passes over this shaft and is connected to a motor 25. The shaft 16 which operates the beam 11 is provided with a sprocket 26, adapted to mesh with the chain forming a part of the conveyor.

The electrical circuits forming a part of the invention are shown in Figure 5 of the drawings. As shown, a main circuit consisting of wires 27 and 28 is connected to a suitable source or current. These wires are provided with branches 29 and 30, connected to the motor. A suitable switch 31 may be arranged therein to permit starting and stopping of the motor. As shown, the wire 29 is connected to a starting rheostat 32. As shown, this member is provided with a rotating contact member 33, one end of which is connected to themotor by a wire 34. The wires 27 and 28 are further provided with a. switch One of these wires is provided with a branch circuit 36, having a relay magnet 37 arranged therein. A bell 38 or other-suitable audible or visible signal may be connected to this circuit by wires 39 and 40. After forming the circuit 36, the wire 28 is extended in proximity to the wire 27. and these two wires are connected to contacts '41 and 42, arranged relatively close to each other on opposite sides of one of the pistons and adapted to be bridged by the contact member 18 when the piston is in lowered position. The wires 27 and 28 are further provided with branches 43 and 44,

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connected to similar contacts and lo, arranged adjacent the other piston rod, and adapted to coact with the contact member 18 of this piston rod in the same manner. The wires 27 and 28 may be further provided with branches -il7 and JCS, connected to a push button 49 or other suitable switch. A pair of branch wires 50 and 51 are connected to the wires 29 and 30. One of these wires is connected to a no-vol'tage release coil 52 arranged adjacent the movable arm 33 ot the starting rheostat. A no-voltage release coil or a magnet switch coil of the ordinary type is employed, depending on whether a hand or automatic starter is used with the motor. From the coil, the wire 50 is connected to a contact 53, arranged adjacent a similar contact 54:, connected to the wire 51. movable switch member 55 is adapted to close these contacts.

The operation of the device is as follows:

\\'hen the conveyor operating, the sprocket 26 meshes with the conveyor chain revolving shat't 16 and rocking the beam ll on its pivot. The pistons (3 are free to move upwardly in the cylinders but are damped on their downward movement, the cylinders serving as dash pots. As a consequence, the pistons and piston rods are moved upward'ly by the engagement of the clips 17 and the nuts 10, and then moved downwardly at a slower rate of speed than the rocking beam. When the conveyor functions in its normal manner, the beam completes its downward movement and returns in sufiicient time to again lift the piston rod before the contact 18 bridges the spaced contact-s. It the conveyor breaks, and the beam comes to a state of rest, one of the piston rods permitted to move downwardly to close the circuit through the wires 27 and 28. This completes the circuit through the branch wire 8,6. connected to the wire 28, giving an audible signal by means of the bell 38. The relay 3? is energized at the same time, moving the contact member 55 to break the circuit 5051. This deenergizes the release coil and releases the movable member 33 ot the rheostat, shut-ting oil the motor. In normal operation, the circuit 51 is energized and the coil 52 retains the movable member 33- of the rheostat in operating position. The motor may be stopped and started by hand or by means 01 switch 31. and the control member may be cut out when desired by means of switch 3:"). The conveyor may likewise be stopped by closing the circuit through branch wires 4 7 and t8, through the push button 49. This coinpletes a circuit through the wires 27 and 28 above the branch wires and through the circuit formed by the branch wire 36.

The invention may be applied to a conveyor in any desired manner. In the term of the conveyor shown, the greatest strain occurs between the driven shaft and the drive shaft on the return flight. If a break should occur, the part of the conveyor passing from the driving sprocket will accumulate between the drive sprocket and the shaft 16 and by placing the shaft 16 at the point indicated, it will be just out of danger of being damaged by congestion of the conveyor parts and in a position where the conveyor generally will come to rest immediately and permit proper functioning of the control. The same principle may be used in determining the location of the device on other types of conveyors, such as vertical or inclined conveyors or compound conveyors. including parts that are horizontal and vertical or inclined.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape. size, and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A control device for conveyors com-- prising a pair of spaced contacts, a movable contact member, a movable member normally connected to the conveyor to retain said contacts in open position, and means for shutting off the power from the conveyor when said movable contact member engages said spaced contacts.

2. The combination with a conveyor and a source of power, of a control device comprising a pair of spaced contacts. a movable contact member adapted to engage said spaced contacts, a member normally connected with the conveyor to n iaintain said movable contact member in disengaged position when the conveyor is operatin and means for disconm cting said conveyor from the source of power when said contacts are closed.

3. The combination with a conveyor and a source of power. normally connected to said convevor. ot' a control device comprising a pair of spaced contacts, a movable contact member adapted to engage said spaced contacts. a rocker arm to maintain said movable contact member in disengaged position, a crank connected to an operative part of said conveyor to rock said arm. and means for disconnecting said conveyor from the source of power when a circuit is completed through said spaced contacts.

4. The combination with a conveyor and a source of power normally connected thereto. 01'' a control device comprising a dash pot. a piston mounted there n. said piston being provided with a. piston rod. a contact member carried by said piston rod. a pair of spaced contacts adapted to be engaged by said contact member when the piston is in lowered position, a rocker arm connected to said conveyor and adapted to re tain said piston in raised position when the conveyor is in operation, and means for disconnecting said conveyor from the source of power when a circuit is completed through said spaced contacts.

5. The combination with a conveyor and a source of power normally connected thereto, of a control device comprising a dash pot, a piston mounted therein, said piston being provided with a piston rod, 1 contact member carried by said piston rod, a pair of spaced contacts adapted to be en- JAMES RAMSEY BUCHANAN.

Witnesses C. L. ALLISON, J. A. GEIsLER. 

